More data from the Purple Line DEIS details the staggering scope of MTA’s rejection of a Jones Bridge BRT alignment for the Purple Line.

CO2 Emission Burden, Percent Change from No-Build Option

Low-Investment BRT (Jones Bridge): 0.00%
Medium-Investment BRT: -0.02%
High-Investment BRT: -0.05%
Low-Investment LRT: 0.04%
Medium Investment LRT: 0.04%
High Investment LRT: 0.04%

Bottom Line: Light rail actually produces slight increases in carbon dioxide emissions because of the power necessary to operate the system. High-investment BRT, which runs buses down the trail, performs best on this measure. But none of the options would deliver any significant changes in carbon dioxide.

Noise

Jones Bridge BRT would have a “modest impact” on Leonard Drive, Wayne Avenue between Cedar Street and Cloverfield Road and Wayne Avenue between Mansfield Road and Sligo Creek Parkway. The other two BRT options would have “modest impact” on Leonard Drive, 16th Street between East-West Highway and Spring Street, Wayne Avenue between Cedar Street and Cloverfield Road, Wayne Avenue between Dartmouth Avenue and Dale Drive, Wayne Avenue between Mansfield Road and Sligo Creek Parkway and Arliss Street between Flower Avenue and Walden Road. All of the light rail options would have “no impact” on noise.

Bottom Line: Light rail is less noisy than buses because of vehicle “skirts” (panels covering the train wheels) and walls on some parts of the alignment.

Capital Cost, 2007 Dollars

Low-Investment BRT (Jones Bridge): $386,390,000
Medium-Investment BRT: $579,820,000
High-Investment BRT: $1,088,480,000
Low-Investment LRT: $1,206,150,000
Medium Investment LRT: $1,220,150
High Investment LRT: $1,634,840,000

Bottom Line: All bus options are cheaper than the rail options. Jones Bridge BRT would cost about one-third of the cheapest rail option and one-quarter of the most expensive rail option.

Annual Operating and Maintenance Subsidy, 2007 Dollars

Low-Investment BRT (Jones Bridge): $14.0 million
Medium-Investment BRT: $12.8 million
High-Investment BRT: $10.6 million
Low-Investment LRT: $21.1 million
Medium Investment LRT: $19.4 million
High Investment LRT: $16.0 million

Bottom Line: The least costly system to operate is high-investment BRT, which runs buses down the trail. The subsidy difference between Jones Bridge BRT (the most costly of the bus options) and high-investment rail is only $2 million per year.

Annual Cost per Hour of User Benefit, 2007 Dollars (FTA Cost Effectiveness)

Low-Investment BRT (Jones Bridge): $18.24
Medium-Investment BRT: $14.01
High-Investment BRT: $19.34
Low-Investment LRT: $26.51
Medium Investment LRT: $22.82
High Investment LRT: $23.71

Bottom Line: The BRT options are more cost effective than the rail options. But the most cost effective option is medium-investment BRT, which would run buses on the trail.

My Take on the DEIS
The DEIS is a sweeping rejection of the arguments for a Jones Bridge BRT alignment. Some of its conclusions are supportable but others are not. Its two most problematic components are:

1. Failure to account for more ridership with extra stops
According to the DEIS, the Jones Bridge alignment would have 40,000 daily boardings while high-investment BRT and all rail options would have 60,000 or more. Yet, the Jones Bridge alignment evaluated by the state has an extra station at the Medical Center. And the state never evaluated the impact of a second station at North Woodmont in Bethesda as suggested by the Town. The state’s reasoning is that the greater speed of the other alignments drives up ridership compared to Jones Bridge BRT. But does that completely swamp the ridership increase of one (or two) extra stations to the extent alleged in the DEIS? That may not be likely, especially when one of the extra stops is at the exploding National Naval Medical Center.

2. Failure to study tree impacts
The loss of mature trees on the Capital Crescent Trail is a powerful argument made by the Town. The state’s reaction was to ignore it and promise to count destroyed trees only after the alignment was chosen. This more than anything is evidence of bureaucratic warfare.

On the above two issues, MTA has not fairly evaluated the Town’s arguments. Town residents have reason to feel aggrieved on those grounds.

But the state has one very powerful argument in its favor that rail opponents cannot effectively rebut: a trail-based, grade-separated alignment will inevitably be faster. The Connecticut-Jones Bridge intersection is one of the most congested intersections in the county. Park and Planning found that northbound evening rush-hour traffic moved at 6.1 miles per hour on Connecticut in the vicinity of the intersection. This horrendous intersection is effectively quicksand for buses.

Town consultant Sam Schwartz recommends prioritizing buses at traffic signals to move them through the intersection as a solution. But that will not help buses stuck in long queues on Jones Bridge Road and it may further congest north-south traffic (causing a disaster for Kensington commuters). The ultimate solution would be to grade-separate the intersection, but that would dramatically increase the Jones Bridge alignment’s cost.

The speed advantage of lane-dedicated, grade-separated trains based on the trail alignment has a ripple effect on many other numbers, including ridership, reductions in traffic, user benefits and cost effectiveness. That alone makes a compelling case for MTA’s evidently preferred options without engaging in bureaucratic games over the extra Jones Bridge stations and tree loss. The speed and performance superiority of rail make it the better option for the Purple Line provided that the politicians will pay for it. After all, while many politicians have signed a pledge to support light rail, few in the state delegation have publicly stated their willingness to raise taxes to fund it.

Rail opponents disagree with the facts contained in the DEIS (and have done so on this blog). But the DEIS has reinforced the most important set of facts concerning the Purple Line: the overarching political climate. More in Part Five.

Update: The Planning Board voted 4-1 today to endorse medium-investment light rail.